For an in-cell capacitive touch display device, a touch function is integrated into each pixel, so a touch electrode of a capacitive touch panel is spaced apart from a liquid crystal layer at a micrometer level. As a result, an electric field generated during the operation of the capacitive touch panel may easily interfere with the rotation of liquid crystal molecules and the coupling of the touch electrode and a pixel electrode, and the pixel electrode may be charged disorderly, so an image may be displayed abnormally (similarly, an electric field generated during operation of a liquid crystal panel may also interfere with an electric field of the touch electrode and may be coupled to the touch electrode). Hence, in the in-cell capacitive touch device, a display operation and a touch operation need to be performed in a time-division manner.
In the related art, in the case that a touch display panel includes L gate lines and M touch scanning lines (L and M are each a positive integer greater than 1), a method for driving the touch display panel includes reserving a blank time period in a time period for displaying each image frame by the touch display panel, so as to perform a touch scanning operation on the M touch scanning lines within this blank time period, as shown in FIG. 1. In other words, the time period T for displaying each image frame is divided into a display time period T1 in which the L gate lines are driven and a touch time period T2 in which the M touch scanning lines are driven. However, the time period for the touch scanning is limited within the time period for display each image frame, so the sensitivity and the report rate are relatively low, and the touch performance of the touch display panel will be adversely affected.